diff --git a/.drone.yml b/.drone.yml
index 97f0061..81c545a 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -1,3 +1,5 @@
+# -*- fill-column: 1000 -*-
+
 kind: pipeline
 name: build x86_64
 
@@ -23,7 +25,6 @@ steps:
   - alias apt-get='rm -f /var/cache/apt/archives/lock && apt-get'
   - apt-get update -q
   - echo "APT::Default-Release \"stretch\";" >> /etc/apt/apt.conf.d/00default_release
-  - echo "deb http://deb.debian.org/debian sid main" >> /etc/apt/sources.list.d/sid.list
   - echo "deb http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu xenial main" >> /etc/apt/sources.list.d/ubuntu-toolchain-r.list
   - apt-get install -qy gnupg
   - gpg --keyserver hkp://keyserver.ubuntu.com --recv-keys 0x60c317803a41ba51845e371a1e9377a2ba9ef27f
@@ -40,6 +41,31 @@ steps:
   - name: debian-package-cache
     path: /var/cache/apt/archives
 
+- name: gcc9
+  image: debian:stretch-slim
+  pull: always
+  environment:
+    CXX: g++-9
+    CXXFLAGS: -pipe -O2
+    LANG: en_US.utf-8
+  commands:
+  - rm /etc/apt/apt.conf.d/docker-clean
+  - alias apt-get='rm -f /var/cache/apt/archives/lock && apt-get'
+  - apt-get update -q
+  - echo "APT::Default-Release \"stretch\";" >> /etc/apt/apt.conf.d/00default_release
+  - echo "deb http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu xenial main" >> /etc/apt/sources.list.d/ubuntu-toolchain-r.list
+  - apt-get install -qy gnupg
+  - gpg --keyserver hkp://keyserver.ubuntu.com --recv-keys 0x60c317803a41ba51845e371a1e9377a2ba9ef27f
+  - gpg --armor --export 0x60c317803a41ba51845e371a1e9377a2ba9ef27f | apt-key add -
+  - apt-get update -q
+  - apt-get install -qy -t xenial g++-9
+  - apt-get install -qy cmake pkg-config libconfig++-dev libxdg-basedir-dev catch
+  - rm -rf build && mkdir -p build && cd build
+  - cmake -DWITH_TESTS=YES -DWITH_EXAMPLES=YES ..
+  - make VERBOSE=1
+  - make install DESTDIR=install
+  - cd tests && ctest -Q
+
 - name: notify
   image: drillster/drone-email
   pull: always